Abstract

Recent discovery of substrate-selective growth of carbon nanotubes on in exclusion to Si, has opened up the possibility of organizing nanotubes on patterns in premeditated configurations for building devices. Here, we report the strong dependence of nanotube growth on the layer thickness, and the utility of this feature to build three-dimensional architectures. Our results show that there is no detectable nanotube growth on layers with thickness less than ∼5–6 nm. For the nanotube growth rate increases monotonically with increasing oxide thickness, and then saturates as approaches >50 nm. We grew nanotubes with multiple lengths at close proximity in a single step by using substrates with regions of different Such processing strategies would be attractive for creating nanotube mesoscale architectures for device applications.